Flexible display device

ABSTRACT

A flexible display device includes a flexible display panel, a flexible printed circuit board extending from the display panel, an integrated circuit chip that is mounted on at least one surface of the flexible printed circuit board and is configured to drive the display panel, and a protection member attached to a rear surface of the display panel. When the flexible printed circuit board is flexed to be partially positioned on the rear surface of the display panel, the protection member is positioned between the display panel and the integrated circuit chip. The flexible display device prevents the integrated circuit chip stacked with the display panel from making direct contact with the display panel using the protection member. Thus, even if the display device is deformed into, for example, a flexed or rolled state, it is possible to prevent the display panel from being damaged.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 15/646,040,filed Jul. 10, 2017, which is a continuation of application Ser. No.14/210,073, filed Mar. 13, 2014, now U.S. Pat. No. 9,736,931, whichpriority to Korean Application No. 10-2013-0026693, filed Mar. 13, 2013,the entire contents of each are hereby incorporated by reference.

BACKGROUND 1. Field

The present disclosure relates to a display device, and particularly, toa flexible display device which can be deformed into a flexed or rolledstate.

2. Description of Related Art

A device such as an imaging device or a portable phone outputs andprovides a picture to a user. For this purpose, such a device isprovided with a display device. A liquid crystal display device commonlyreferred to as a “Liquid Crystal Display (LCD)” is configured in a flatshape and widely used in television sets, computer or notebook monitors,portable terminals or the like as a display device. As elements such asthin film transistors or organic light emitting diodes are developed,such flat display devices have become thinner and implement a sharperpicture.

Recently, portable terminals have developed to provide multimediaservices through mobile communication networks. Accordingly, in order toprovide a larger picture, the portable terminals also use a displaydevice capable of outputting a larger picture. As the display device isenlarged in a portable terminal for which miniaturization and lighteningare essentially used, efforts to reduce the thickness of the portableterminals have continued in order to secure portability.

If a display device is flexible, it will be possible to carry thedisplay device in a flexed, folded, or rolled state. Thus, the flexibledisplay device will be capable of greatly contributing to securingportability of a portable terminal while enlarging the screen of theportable terminal. Accordingly, research to make a display deviceequipped with a flexible display panel commercially available isrecently being strengthened.

In configuring a flexible display device, it will be necessary toarrange, for example, various circuit boards, the display device, andintegrated circuit chips in such a manner that flexibility can bemaintained. For example, even if a display panel is flexible, thedisplay will not be substantially flexible if the circuit boards and theintegrated circuit chips, each of which has a considerable surface area,are not flexible when they are laminated on the display panel.Accordingly, if it is desired to implement a flexible display device,the circuit boards laminated on the flexible display panel should alsobe flexible, and the integrated circuit chips should be fabricated in asufficiently small size and arranged not to affect the deformation ofthe display panel.

Further, when designing the sizes and arrangements of the circuit boardsand the integrated circuit chips to satisfy such conditions, the displaypanel should be prevented from being damaged. For example, when thedisplay device is deformed into a flexed or rolled state, it is obviousthat in the laminated structure, the spaces between the display paneland each of the circuit boards and integrated circuit chips will benarrowed compared to the spaces in the state where the display device isnot deformed. Accordingly, depending on the degree of deformation of thedisplay device, the integrated circuit chips may interfere with and comeinto contact with the display panel causing damage to the display panel.Further, in view of the characteristics of the flexible display device,it is obvious that the display device may be locally deformed by, forexample, an external shock. Such a local deformation may cause theintegrated circuit chips to come into contact with the display deviceand cause damage to it.

SUMMARY

To address the above-discussed deficiencies, it is a primary object toprovide a display device which is capable of preventing damage of adisplay panel while retaining flexibility.

In addition, the present disclosure is to provide a display device whichis reduced in thickness to improve flexibility.

Further, the present disclosure is to provide a display device which hasan improved degree of freedom in arranging integrated circuit chips orthe like while retaining flexibility.

Accordingly, the present disclosure discloses a flexible display deviceincluding: a flexible display panel; a flexible printed circuit boardextending from the display panel; an integrated circuit chip that ismounted on at least one surface of the flexible printed circuit boardand drives the display panel; and a protection member attached to a rearsurface of the display panel.

When the flexible printed circuit board is flexed to be partiallypositioned on the rear surface of the display panel, the protectionmember is positioned between the display panel and the integratedcircuit chip.

The flexible printed circuit board may be interposed between theintegrated circuit chip and the protection member.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document: the terms “include” and “comprise,” aswell as derivatives thereof, mean inclusion without limitation; the term“or,” is inclusive, meaning and/or; the phrases “associated with” and“associated therewith,” as well as derivatives thereof, may mean toinclude, be included within, interconnect with, contain, be containedwithin, connect to or with, couple to or with, be communicable with,cooperate with, interleave, juxtapose, be proximate to, be bound to orwith, have, have a property of, or the like; and the term “controller”means any device, system or part thereof that controls at least oneoperation, such a device may be implemented in hardware, firmware orsoftware, or some combination of at least two of the same. It should benoted that the functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely.Definitions for certain words and phrases are provided throughout thispatent document, those of ordinary skill in the art should understandthat in many, if not most instances, such definitions apply to prior, aswell as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates a vertical cross-sectional view of a configuration ofa flexible display device according to an example embodiment of thepresent disclosure;

FIG. 2 illustrates a vertical cross-sectional view of a configuration ofa modified example of the flexible display device illustrated in FIG. 1;and

FIG. 3 illustrates a vertical cross-sectional view of a configuration ofa flexible display device according to another example embodiment of thepresent disclosure.

DETAILED DESCRIPTION

FIGS. 1 through 3, discussed below, and the various embodiments used todescribe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system and method. Hereinafter,various embodiments of the present disclosure will be described indetail with reference to the accompanying drawings. For the purposes ofclarity and simplicity, a detailed description of known functions andconfigurations incorporated herein will be omitted as it may make thesubject matter of the present disclosure rather unclear.

A display device according to the present disclosure includes a flexibledisplay panel, a flexible printed circuit board that connects a drivingcircuit chip such as an integrated circuit chip that drives the displaypanel or a main circuit board to the display panel, and a protectionmember. Considering that the display device is flexible, it is obviousthat the main circuit board should also be made of a flexible material.In such a case, the flexible printed circuit board may be disposed to bebent to be partially positioned on a rear surface of the display panel,in which case the protection member is positioned between the flexibleprinted circuit board and the display panel.

As a result, the protection member protects the rear surface of thedisplay panel to prevent the integrated circuit chip mounted on theflexible printed circuit board and the main circuit board connected tothe flexible printed circuit board from interfering with or coming intocontact with each other. Further, when a printed circuit pattern isformed on each surface of the flexible printed circuit board, integratedcircuit chips connected to the display panels may be disposed on eithersurface of the flexible printed circuit board. Accordingly, thearrangement of the integrated circuit chips may be more freely designed.

FIG. 1 illustrates a vertical cross-sectional view of a configuration ofa flexible display device 100 according to an example embodiment of thepresent disclosure, and FIG. 2 illustrates a vertical cross-sectionalview of a configuration of a modified example of the flexible displaydevice 100 illustrated in FIG. 1. The display devices 100 illustrated inFIGS. 1 and 2 are similar to each other in configuration merely exceptfor the arrangements of main circuit boards 133. Accordingly, it shallbe noted that the same or similar components will be assigned with thesame reference numerals in describing the display devices 100illustrated in FIGS. 1 and 2.

As illustrated in FIG. 1, the flexible display device 100 according toan example embodiment of the present disclosure includes a flexibledisplay panel 101, a flexible printed circuit board 103 of which a partextends from the flexible display panel 101 and is positioned on a rearsurface of the display panel 101, and a protection member 105 interposedbetween the part of the flexible printed circuit board 103 and thedisplay panel 101.

The display panel 101 may be configured using an Organic Light EmittingDiode (OLED) element and provided with light emitting film 111 attachedto a surface of a base film 113. The light emitting film 111 is anelement that practically outputs a picture and may be made of apolyimide film on which a thin film transistor or the like is arranged.In general, a display panel is configured such that the light emittingfilm is disposed on each of the front and rear surfaces of the lightemitting film. However, the display panel 101 is configured such that abase film 113 made of a synthetic polymer resin and a Thin FilmEncapsulation (TFE) 115 are disposed on the front and rear surfaces ofthe light emitting film 111, respectively. Accordingly, unlike anordinary flat display panel, the display panel 101 is deformable into,for example, a flexed or rolled state to take a curved shape and mayoutput a picture even after being deformed.

Further, the display panel 101 may be provided with apolarization-functional film, for example, a Polyvinyl Alcohol (PVA)film 117 and, although not illustrated, may also be provided with aTri-Acetyl Cellulose (TAC) or the like that protects the PVA film 117.The detailed configuration of the display panel 101 somewhat departsfrom the gist of the present disclosure and, thus, a detaileddescription thereof will be omitted. In other words, the flexibledisplay device 100 according to the present disclosure may also beconfigured using any type of flexible display panel.

When it is desired to incorporate a touch screen function in the displaydevice 100, a touch screen window 102 may be disposed on the displaypanel 101. The touch screen window 102 has a configuration in which atransparent electrode film, for example, an Indium-Tin Oxide (ITO) film123 is attached to a window member 121 to protect the display panel 101while providing a touch screen function. The ITO film 123 detects auser's input action and transfers the input action through a separatecircuit board 125 and an integrated circuit chip 127. When the touchscreen function is not incorporated in the display device 100, the ITOfilm 123 does not have to be disposed.

The ITO film 123 may be attached to the PVA film 117 by lamination. Forthis purpose, a laminating film 129 may be interposed between the ITOfilm 123 and the PVA film 117.

The protection member 105 is attached to the rear surface of the displaypanel 101 to protect the display panel 101. The protection member 105 isfabricated in a film shape using aluminum, magnesium or the like toensure that the protection member 105 may retain its flexibility whilebeing attached to the display panel 101. Alternatively, when theprotection member 105 is made of an elastic material, external shock maybe dispersed. When the protection member 105 is attached to the rearsurface of the display panel 101, the integrated circuit chip 135 or thelike mounted on the flexible printed circuit board 103 may be preventedfrom making direct contact with the display panel 101 even if theflexible printed circuit board 103 is partially positioned at the rearside of the display panel 101.

The flexible printed circuit board 103 is provided to connect thedisplay panel 101 to the main circuit board 133 including a centralprocessing device or the like, and dispose the integrated circuit chip135 including a driving circuit chip thereon. In configuring theflexible printed circuit board 103, it is desirable to form printedcircuit patterns 103 a and 103 b on the both surfaces of the flexibleprinted circuit board 103 in which the printed circuit pattern(hereinafter, referred to as a “first printed circuit pattern”) 103 aformed on one surface and the printed circuit pattern (hereinafter,referred to as a “second printed circuit pattern”) 103 b formed on theother surface are electrically connected with each other a via holeformed through a board film 131 of the flexible printed circuit board103, a metallic layer or the like.

When the printed circuit patterns 103 a and 103 b are formed on the bothsurfaces of the flexible printed circuit board 103, respectively, theintegrated circuit chip 135 or the main circuit board 133 may bedisposed either surface of the flexible printed circuit board 103. Ofcourse, the first and second printed circuit patterns 103 a and 103 bwill be differently designed depending on the surface or position wherethe integrated circuit chip 135 or the main circuit board 133 isdisposed. Accordingly, it is possible to improve a degree of freedom ofdesign in arranging the integrated circuit chip 135 or the main circuitboard 133.

The first printed circuit pattern 103 a is directly connected to thedisplay panel 101 and the integrated circuit chip 135 is mounted on thesurface of the flexible printed circuit board 103 where the secondprinted circuit pattern 103 b is formed. Accordingly, when theintegrated circuit chip 135 is positioned on the rear surface of thedisplay panel 101, the protection member 105 and the flexible printedcircuit board 103 are interposed between the integrated circuit chip 135and the display panel 101. In other words, the integrated circuit chip135 does not directly face the display panel 101 even if it is disposedon the rear surface of the display panel 101. Consequently, even if thedisplay device 100 is deformed, the protection member 105 and theflexible printed circuit board 103 prevent the integrated circuit chip135 being interfered with the display panel 101.

The flexible printed circuit board 103, and in an embodiment, a part ofthe board film 131, is attached on the rear surface of the display panel101. An adhesive layer 139 may be formed between the flexible printedcircuit board 103 and the protection member 105 so as to fix theflexible printed circuit board 103 on the rear surface of the displaypanel 101.

As described above, the main circuit board 133 is preferably made of aflexible board material. FIG. 1 illustrates a configuration in which themain circuit board 133 is disposed on the one surface and FIG. 2illustrates a configuration in which the main circuit board 133 isdisposed on the other surface. When the main circuit board 133 isdisposed on the other surface of the flexible printed circuit board 203,an adhesive layer 239 may be formed between the main circuit board 133and the protection member 105. The adhesive layer 239 formed between themain circuit board 133 and the protection member 105 is formed to be asthick as the flexible printed circuit board 203.

The display device 100 as described above may be provided with a bracket104 that protects the display panel 101, the flexible printed circuitboard 103 or 203, and the like. The bracket 104 is provided to encloseat least the protection member 105, preferably the rear surface and theperiphery of the display panel 101. When the integrated circuit chip135, the main circuit board 133 or the integrated circuit chip 137mounted on the main circuit board 133 protrudes from the flexibleprinted circuit board 103 or 203, it is desirable to form anaccommodation recess 141 on the bracket 104 to accommodate theprotruding integrated circuit chip, and the like.

When the bracket 104 is disposed, the display device 100 takes a singlemodule shape, and in a real product manufacturing, it is also desirableto provide the bracket 104. When the accommodation recess 141 is formedto accommodate the integrated circuit chip 135 and the like, theincrease of thickness of the display device 100 may be minimized eventhough the bracket 104 is stacked with the display panel 101, theintegrated circuit chip 135, and the like.

FIG. 3 illustrates a vertical cross-sectional view of a configuration ofa flexible display device 300 according to another example embodiment ofthe present disclosure. The flexible display device 300 according to thepresent example embodiment is different from the prior exampleembodiments in that a protection member is also used as a bracket.Accordingly, it shall be noted that the components which may be easilyunderstood from those of the prior example embodiments may be assignedwith the same reference numerals or may not be assigned a referencenumeral and the detailed descriptions thereof may be omitted.

The protection member 305 is formed such that one surface facing thedisplay panel 101 is flat. Accordingly, it is easy to attach the displaypanel 101 to the protection member 305. In addition, since the flexibledisplay panel 101 is attached and fixed to the flat surface, a uniformcurvature radius may be secured when the flexible display panel 101 isdeformed into a flexed or rolled state. In other words, before and afterdeformation, an unnecessary flexure may be prevented from beinggenerated on the display panel 101. An adhesive layer 339 is providedbetween the display panel 101 and the protection member 305 so as toadhere and fix the display panel 101 to the protection member 305.

The flexible printed circuit board 303 extending from the display panel101 of the display device 300 extends to enclose the periphery of theprotection member 305. Accordingly, a part of the flexible printedcircuit board 303 is positioned to face the other surface of theprotection member 305. The integrated chip 135 such as the drivingcircuit chip of the display panel 101 or the main circuit board 133 maybe mounted on a surface of the flexible printed circuit board 303 to bepositioned to face the other surface of the protection member 305. Onthe other surface of the protection member 305, it is desirable to forman accommodation recess 351 that accommodates the integrated circuitchip 135 mounted on the flexible printed circuit board 303 or the maincircuit board 133.

A flexible display device configured as described above prevents anintegrated circuit chip stacked with a display panel from coming intodirect contact with the display panel using a protection member. Thus,even if the display device is deformed into, for example, a flexed orrolled state, it is possible to prevent the display panel from beingdamaged. That is, the damage of the display panel may be prevented inthe course of fabricating the display device or during use of the finalproduct. Further, in configuring a flexible printed circuit board onwhich an integrated circuit chip is mounted, when a printed circuitpattern is formed on each surface of the flexible printed circuit board,the integrated circuit chip may be disposed to face the display panelwith the flexible printed circuit board being interposed therebetween.As a result, a degree of freedom of design in arranging the integratedcircuit chip may be improved. Moreover, when an accommodation recess isformed on a bracket provided to enclose the protection member or thedisplay panel so as to accommodate the integrated circuit chip, and thelike, an increase of thickness by the integrated circuit chip may besubstantially prevented. Therefore, it is easy to reduce the thicknessof the display device. The reduction of thickness of the display devicemay contribute to improving the flexibility of the display deviceallowing it to more easily be flexed or rolled.

Although the present disclosure has been described with an exampleembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

What is claimed is:
 1. A flexible display device comprising: a flexibledisplay panel; an integrated circuit chip; a flexible printed circuitboard extending from the flexible display panel and provided to connectthe integrated circuit chip and the flexible display panel, theintegrated circuit chip mounted on a first surface of the flexibleprinted circuit board and is configured to drive the flexible displaypanel; a bracket attached, on a first side of the bracket, to a rearsurface of the flexible display panel and configured to enclose at leasta part of the flexible display panel including a periphery of theflexible display panel; and an accommodation space that accommodates theintegrated circuit chip mounted on the flexible printed circuit boardfor preventing the integrated circuit chip, including its top andsurrounding surfaces, from coining into direct contact with otherelements, wherein the accommodation space is formed on a second side ofthe bracket opposite to the first side, wherein the integrated circuitchip is accommodated in the accommodation space at a position between aportion of the flexible printed circuit board and the bracket, wherein,the integrated circuit chip is disposed below the flexible display paneland the bracket, and at least part of the flexible printed circuit boardis disposed below the bracket, and wherein the flexible printed circuitboard includes a circuit pattern formed on the first surface anddirectly connected to the integrated circuit chip and the flexibledisplay panel.
 2. The flexible display device of claim 1, furthercomprising: a main circuit board provided at an end of the flexibleprinted circuit board, wherein, when the flexible printed circuit boardis partially positioned on a rear surface of the flexible display panel,the main circuit board is disposed to at least partially face thebracket.
 3. The flexible display device of claim 2, wherein at least apart of the main circuit board is accommodated in the accommodationspace.
 4. The flexible display device of claim 1, wherein the rearsurface of the flexible display panel is disposed to face the firstsurface of the bracket.
 5. The flexible display device of claim 4,wherein the first surface of the bracket facing the flexible displaypanel is flat.
 6. The flexible display device of claim 5, furthercomprising an adhesive layer formed between the flexible display paneland the bracket.
 7. The flexible display device of claim 1, wherein thebracket is provided to enclose the periphery and the rear surface of theflexible display panel.